Traumatic Brain Injury (TBI) is one of the major public health and socioeconomic problems in both developed and developing countries. In the US alone, an estimated 1.7 million civilians sustain TBI each year, and in Europe, an average aggregate hospitalization and fatal TBI incidence rate of 235 per 100,000 people per year has been reported. Most TBI cases (70-90%) are classified as mild traumatic brain injury (mTBI), which is often synonymous with concussion. Globally, the incidence of hospital-treated patients with mTBI is 100-300 per 100,000 people per year. However, it has been estimated that the actual population-based rate of mTBI is likely to be above 600 per 100,000 people because many individuals sustaining an mTBI do not seek the hospital treatment or do not report the injury. In the military, it has been estimated that 5-35% of American service members deployed to Iraq and Afghanistan sustained an mTBI, with 80% of these injuries being secondary to blast exposures.
mTBI represents a significant diagnostic challenge. Current diagnosis is subjective and frequently based on self-reported neurological symptoms, some of which could be ignored, concealed, or overstated. This problem is especially magnified in children, as they may have trouble in recognizing and/or defining their symptoms. Accordingly, there is a great need to identify biomarkers that would provide physicians with objective tools for the diagnosis of patients sustaining concussions.